A surveillance camera has an imaging unit on a base member which is fixed on a placing surface. When transmitting and receiving a signal between the base member and the imaging unit, the signal has been transmitted and received via a slip ring built in the surveillance camera.
However, an existing slip ring brings a circular electrical path which is concentrically arranged with respect to a rotating body into contact with a brush to transmit the signal between the electrical path and the brush, sometimes leading to a case of unstable signal transmission. Therefore, quality of the signal disadvantageously has deteriorated in some cases when the signal is transmitted at a high speed.